1. Field of the Invention
The present invention relates to an optical imaging lens assembly, which can provide a wider viewing angle, reduced sensitivity of the optical system and higher resolution, utilized in portable electronics.
2. Descriptions of the Related Art
With the widespread use of portable electronic products over recent years, portable electronic products with a photographing function have particularly gained great popularity among consumers. For the purpose of meeting consumers' demand regarding the performance of pixels and picture quality, the development of miniaturized photographic lenses has become more important.
For the common photographic lens, a photosensitive element used therein is either a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) sensor. Moreover, as semiconductor manufacturing technologies have advanced in great magnitude, the pixels of the photosensitive elements are further reduced in size, which can provide a greater number of pixels for miniaturized photographic lens systems. Therefore, the demand on high quality imaging devices increases with an even faster pace.
As illustrated in U.S. Pat. No. 7,397,612, conventional photographic lenses with a wide viewing angle, which are disposed in portable electronic products, mostly adopt an inverse telephoto structure in which the front lens assembly has negative refractive power and the rear lens assembly has positive refractive power to obtain a wide viewing angle for imaging a larger area. However, an optical system that adopts the three-lens configuration still has shortcomings in terms of optical imaging quality as compared to a four-lens optical system and, consequently, fails to meet the requirement on the optical imaging quality.
Furthermore, as illustrated in U.S. Pat. No. 7,446,955, a four-lens optical system, which can provide a wide viewing angle of nearly 140 degrees, is disclosed. However, a stop thereof is disposed at the back end of the optical system and is very close to the image plane. Moreover, the one lens element that is disposed behind the stop for aberration compensation has a limited correction capability, thereby, having an adverse effect on the imaging quality.
In view of this, an urgent need exists in the art to provide an optical imaging lens assembly with a wide viewing angle, superior imaging quality and a desirable total track length.